Dust separation



March l, 1932. A, F WENDLER DUS T SEPARAT I ON Filed May 14, 1926Enz/@Wr A.F. WENL. y

Patented Mar. v1, 1932 UNITED STATES PATENT oFFlcE ADOLPBI F. WENDLER,OIF BUFFALO, NEW YORK, ASSIGNOB TO NATIONAL ANILINE & CHEMICAL CO.,INC., OF NEW YORK, N. 2'., .Ay CORPORATION 0F NEW YORK DUST SEPARATION.Application filed Kay 14, 1928. .Serial No. 109,088.

This invention relates to the separation of dust from gases and therecovery of the separated dust. j

Dusting, or the entrainment of dust in the vapors drawn from a drier oran equivalent operation, is a condition're uiring correction not only toavoid pollution ut to recover the values present. For this puropse,cloth filtersl are found most desirable; they have the disadvantage,however, that they rapidly become clogged with dust which must beremoved in some manner. One method adopted is a freuent reversal of thegas current to dislodged ust from the cloth, but obviously thisinterferes with the drier or with other operations being carried out. Afurther disadvantage is that some of the dust passes throu h the clothand this in time builds up a dust eposit on the departure side of thecloth as well as on the approach side and effectively interferes withthe gas or vapor iow.

Itis an object of this invention to provide a dust separation that issubstantially automatic and largely obviates handling of the dust. Afurther object is the use of cloth filters for this urpose so interposedin the path of a dust la en gas current that dust is substantiallgremoved on the approach side of the filter. `further object is amounting of a cloth filter for discharging separated dust withoutnecessitating reversals of the gas' current, and automatically returningdust to the apparatus giving rise thereto.`

Another object is an arrangement that promotes separation of dust on thedeparture side as well as the approach side of the filter. Anotherobject is an arrangement that provides for the read removal of dustcollected on the departure side of the filter; These and other objectswill appear from the following description.

In general, these objectsl are accomplished .A by the suspension of aclo'tliiltr iii-the path of an upwardly flowing gas current, theadoption of a depending bag form of filter, and the revisionV of a sideoutlet beyond the filter. ithy an upwardly moving gas current, theseparated dust is held to the bag only by its adhesion and the pressureof the gas current. As the dust accumulates the particles the flange orledge 16.

agglomerate and their weight increases until 1t 1s sufficient toovercome these effects and the se arated dust accordingly flakes oil andis pre erably returned directly to the drier or equivalent apparatus toavoid handling. The bag form of filter not only presents an extendedarea of contact, creating a relatively quiescent zone in close proximityto the filter, but it deiiects the gas current in its passagetherethrough thus furthering dust separation; this action is accentuatedby the pas-- sage of the as current inward of the bag.A The side outatabove the bag causes further deviation with consequent dustprecipitation and also aiords a clear passage for `the recasing.

In the accompanying drawings Fig. 1 is a top view partly in section:

Fig. 2 is a vertical cross section on line 2--2 of Fig. 1; and

Fig. 3 is a section on line 3 3 of Fig. 2.

A cylindrical casing 10 has a lower hopper shaped portion 11 with aanged bottom opening 12 to be bolted to the vapor outlet 13 of a drier.While designed for use with a drier, it is apparent that the structureis useful with other types of apparatus, or in addition to a dustcollector. At the up er end 'of the cylindrical portion is a lateraoutlet cover and the casing. For cutting oifthe 4 suction and supplyinga reverse current of air a branch line 25 controlled by a valve 26 jisinserted in the suction line 15.

The' bg "member comprises a strapl ring 30 of a size sufficiently smallto fit within the casing but suiliciently lar e to be retained by o thisstrap are secured the upper en ds of U-shaped braces 31, 32; 1u s 33, 34are welded to the edge of the ring. g.[hese lugs have slots 35, 36slightl inclined to engage the projecting ends of lts 37, 38 which arethreaded through the casing wall. A second strap ring 39 of the samesize as the ring forms a clamp with the latter lto holdfbetween them awire mesh 40 and an enclosing `cloth bag 41 maintained in distendedcondition by the braces and the wire mesh; screws or bolts 42 securethefrin gs together.v The bag may be of any suitable materialsuch ashair-cloth, canvas or wool felt, andis preferably of a. character thatdoes not seriously affect thesuction within the drier or equivalentapparatus. The assembly of the braces 3l and 32, wire mesh 40, bag 4l,and rings 30 forms a cup-shaped, or closedv bottom cylindrical,screening member which rests` on the ledge 16, and which, being`ofsmaller cross-sectional area than theteylindrical casing 10, leaves anannular passage 50 for the dust-laden vapors between the bag and thecasing. A removable dowel pin 43 extending through the rings and intothe f flange maybe used to lock the rings in place.

passage 50,` Where they are again detiected by the ledge 1G, on whichthe bag assembly rests, and caused to pass through the Vside walls ofthe bag 41 into the interior of the bag. As the outlet 14 of the easingis' above the top of the bag and laterally beyond its periphery 'thevaporspassingthrough the bag must again change their direction inleaving the chamber. The separated dust agglomerates on the outside ofthe bag, and due to its own weight and vibration of the bag drops fromthe bag back into the drier to mix with the original charge. The actionis accordingly substantially automatic and avoids handling of thegreater portion of the dust. Some of the dust particles are drawnthrough the cloth mesh and the relatively quiescent condition near thecloth surface promotes their separation; the defiection of the gascurrent above the bag aids Vfi'urther separation of dust. AS the bag'islocked to the casing, the suc tion does not displace it and the metalform, about which the bag is drawn7 holds the latter in a distendedcondition." At the end of a drying or other operation, airis admitted todestroy the suction; and the reversed gas current so created is passedthrough the bag which not only returns dust particles, drawn into thecloth meshes and clinging to the eX- terior of the bag, but .alsopromotes settlement of dust within the bag. Accordingly when the casingis opened by throwing back the cover, the bag with the contained dust isreadily lifted from thecasing without the inconvenience and annoyance ofsubstantial amounts of free dust in the atmosphere. Presence of steam orother vapor does not interfere with the dust separation, particularly ifa heat insulating jacket is provided to prevent undue condensation.

I claim:

1. A dust separation apparatus including in'combination a casing havingan outlet, a seat extending from the inner wall of said easing belowsaid outlet, a depending ba lr filter detachably supported by a ring onsaid seat,` said bag enclosing a wire mesh and being maintainedvin adistended condition against said wire mesh by means of U-shaped bracesextending from said ring, and means for introducing dust laden gas intosaid casing below said seat. Y

E2. A dust separation apparatus including in combination a easing havinga gas inlet and a gas outlet, a seat extending from the inner wall ofsaid casing, a strap ring resting on said seat and supporting afiltering medium, a wire mesh enclosed by said filtering 'medium andsupported from said ring, braces extending from said ring for supportingsaid .filtering medium in an extendedcondition, a spider hinged to thetop of said easing and a cover hinged to said spider.

SSA method of dust separation which comprises' passing a gas flowingupwardly from a vessel and laden with dust through a filter'- ing mediumto separate dust, removing dust separated by said medium from saidmedium and causing it to return to the vessel, and deflecting the gascurrent after its passage through the medium to separate additional dustin'a zone above the filtering medium, whereby said additional dust fallsupon said filtering medium.

4. In an apparatus for the removal 'of dust from the vapors given ofi'by a drier for solid material, the combination' of a cylindrical easingopen at the bottom'and the top. said bottom opening forming an inlet forthe dustladen vapors, means on said casing for mounting it directlyabove the drier 1n the vapor-discharge line thereof, a ledge on theinner wall of the casing, a bag filter depending from the ledge andforming with the casing an annular passage closed at its top, saidfilter being removable through the opening in the top of the casing, anoutlet in the wall of the easing above the bag filter, and a cover forthe opening inthe top ot the casing.

In testimony whereof I afiix my signature.

ADOLPH F. VVENDLER.

